1. Field of the Invention
The present invention relates to a power compensating device that makes up for any extreme reduction in the voltage of the batteries loaded, for example, on cars and small vessels due to any large fluctuation in load.
2. Description of the Prior Art
In the event that such a large load 11 as a car amplifier and speaker of the order of several hundreds of watts is connected to the battery 10 with capacity equivalent to those loaded, for example, on passenger cars via a long 2 to 5 m cable 13 as shown in FIG. 6, a sharp voltage drop may be caused by the resistivity of the cable 13, if a large current flows into the large load 11. Suppose a large current, for example, of 20 to 30 A or even higher flows into an ordinary car battery 10 of Vi (12 V, for instance) at the time of t1 as shown in FIG. 5, and the current returns to its original value at the time t2 due to an extreme fluctuation in voltage. If there exists no compensating capacitor 8, a temporary voltage drop V1 of 10 to 20% occurs against the supply voltage Vi as shown by the dotted characteristic lines in FIG. 5, thereby causing short of power, reduction in tone quality and distortion.
To solve this problematical point of temporary excessive voltage drop, conventionally a compensating capacitor 8 has been inserted between the power supply input terminals of the load 11 as shown in FIG. 6.
When in such a circuitry a large current flows into the load 11 at the time t1 as in FIG. 5 and a sharp voltage drop is about to occur, the energy accumulated in the compensating capacitor 8 is released to decrease the voltage relatively gently down to V2 as shown by the characteristic two-dot chain curve in FIG. 5, and further the same voltage rises up also gently from the time t2 to its original level.
The prior art was problematical, however, in that though this insertion of the compensating capacitor 8 allows for a voltage drop suppression effect to a certain extent, the sole compensating capacitor 8 requires a substantially long cable 13 to connect the battery 10 and load 11. This long cable tends to reduce the voltage. To make up for this voltage drop, the electric charge stored in the compensating capacitor 8 is consumed making it insufficient to suppress the fluctuation in voltage.
The primary purpose of this invention is to provide a power compensating device for battery that can control enough the extreme voltage drop by a comparatively simple circuitry.
The second purpose of this invention is to provide a device that can readily set a target value in terms of the voltage fluctuation to be controlled and the size of load depending on whether or not any referential voltage is to be selected from among plural settings.
The third objective of this invention is to provide a device that allows us to know visually the suppression effects of multistaged fluctuation in voltage.
The fourth objective of this invention is to supply a device that allows us to set the voltage compensating value, crude or fine, upon request.
The fifth purpose of this invention is to reduce as far as possible the internal resistance of compensating and auxiliary capacitors even if their capacities may be the same.
Other and further objects, effects and advantages of this invention will appear more fully from the following optimal embodiments.